An inflatable vehicle occupant protection device, such as a side curtain or an air bag, is inflated upon the occurrence of a vehicle condition requiring inflation of the side curtain or air bag. When inflation is required, an inflator is actuated to provide inflation fluid which inflates the side curtain or air bag into the vehicle occupant compartment.
The inflator includes a pressure vessel defining a chamber with a passage for inflation fluid flow from the chamber. A rupturable burst disk is fixed to the container to block flow of inflation fluid through the passage. The inflator further includes an electrically actuatable igniter assembly which, when actuated, bursts the burst disk to enable fluid to flow from the chamber through the passage.